Neil Armstrong and David Scott in the Gemini VIII capsule, after splashdown, March 16, 1966. Credit: NASA.
So, you’ve just endured a harrowing experience where your orbiting spacecraft has gone wildly out of control. You somehow — while undergoing the incredible, vertigo-inducing G-forces of your spinning spacecraft — figure out a plan, undock your spacecraft from another spacecraft and abort your original mission.
Six and a half orbits and ten hours and 44 minutes after you’ve thunderously launched into space, you violently re-enter Earth’s atmosphere and splash down in a pitching ocean. Obviously, you have to throw up, and so does your crewmate. But there’s just one air sickness bag.
But by the time the rescue crew has arrived you’ve donned your sunglasses and look as cool as a cucumber.
That’s Neil Armstrong and Dave Scott’s experience during the Gemini 8 mission.
Apollo 13's dangerous explosion in 1970 inspired a movie, released in 1995, that starred (left to right) Bill Paxton, Kevin Bacon and Tom Hanks. Credit: Universal Pictures
Space is a dangerous and sometimes fatal business, but happily there were moments where a situation happened and the astronauts were able to recover.
An example: today (March 16) in 1966, Neil Armstrong and Dave Scott were just starting the Gemini 8 mission. They latched on to an Agena target in the hopes of doing some docking maneuvers. Then the spacecraft started spinning inexplicably.
They undocked and found themselves tumbling once per second while still out of reach of ground stations. A thruster was stuck open. Quick-thinking Armstrong engaged the landing system and stabilized the spacecraft. This cut the mission short, but saved the astronauts’ lives.
Gemini 8’s Agena target before a stuck thruster on the spacecraft put the astronauts in a terrifying tumble. Credit: NASA
Here are some other scary moments that astronauts in space faced, and survived:
Friendship 7: False landing bag indicator (1962)
Astronaut John Glenn views stencilling used as a model to paint the words “Friendship 7” on his spacecraft. Credit: NASA
John Glenn was only the third American in space, so you can imagine the amount of media attention he received during his three-orbit flight. NASA received an indication that his landing bag had deployed while he was still in space. Friendship 7’s Mercury spacecraft had its landing cushion underneath the heat shield, so NASA feared it had ripped away. Officials eventually informed Glenn to keep his retrorocket package strapped to the spacecraft during re-entry, rather than jettisoning it, in the hopes the package would keep the heat shield on. Glenn arrived home safely. It turned out to be a false indicator.
Apollo 11: Empty fuel tank (1969)
Apollo 11’s Eagle spacecraft, as seen from fellow spaceship Columbia. Credit: NASA
Shortly after Neil Armstrong announced “Houston, Tranquility Base, here, the Eagle has landed” during Apollo 11, capsule communicator Charlie Duke answered, “Roger, Tranquility. We copy you on the ground. You got a bunch of guys about to turn blue. We’re breathing again. Thanks a lot.” They weren’t holding their breath just because it was the first landing on the moon; Armstrong was navigating a spacecraft that was almost out of fuel. The spacecraft Eagle overshot its landing and Armstrong did a series of maneuvers to put it on relatively flat ground. Accounts say he had less than 30 seconds of fuel when he landed on July 20, 1969.
Apollo 12: Lightning strike (1969)
Apollo 12’s launch in 1969, moments before the rocket was struck by lightning. Credit: NASA
Moments after Apollo 12 headed from ground towards orbit, a lightning bolt hit the rocket and caused the spacecraft to go into what appeared to be a sort of zombie mode. The rocket was still flying, but the astronauts (and people on the ground) were unsure what to do. Scrambling, one controller suggested a command that essentially reset the spacecraft, and Apollo 12 was on its way. NASA did take some time to do some double-checking in orbit, to be sure, before carrying on with the rest of the mission. The agency also changed procedures about launching in stormy weather.
Apollo 13: Oxygen tank explosion (1970)
Evidence of the Apollo 13 explosion on the service module. Credit: NASA
The astronauts of Apollo 13 performed a routine stir of the oxygen tanks on April 13, 1970. That’s when they felt the spacecraft shudder around them, and warning lights lit up. It turned out that an oxygen tank, damaged through a series of ground errors, had exploded in the service module that fed the spacecraft Odyssey, damaging some of its systems. The astronauts survived for days on minimal power in Aquarius, the healthy lunar module that was originally supposed to land on the moon. They arrived home exhausted and cold, but very much alive.
Apollo-Soyuz Test Project: Toxic vapours during landing (1975)
The Apollo command module used in the Apollo-Soyuz Test Project, during recovery. Credit: NASA
The Apollo-Soyuz Test Project was supposed to test out how well American and Russian systems (and people) would work together in space. Using an Apollo command module and a Russian Soyuz, astronauts and cosmonauts met in orbit and marked the first mission between the two nations. That almost ended in tragedy when the Americans returned to Earth and their spacecraft was inadvertently flooded with vapours from the thruster fuel. “I started to grunt-breathe to make sure I got pressure in my lungs to keep my head clear. I looked over at Vance [Brand] and he was just hanging in his straps. He was unconscious,” recalled commander Deke Slayton, in a NASA history book about the event. Slayton ensured the entire crew had oxygen masks, Brand revived quickly, and the mission ended shortly afterwards.
Mir: The fire (1997)
Jerry Linenger dons a mask during his mission on Mir in 1997. Credit: NASA
The crew on Mir was igniting a perchlorate canister for supplemental oxygen when it unexpectedly ignited. As they scrambled to put out the fire, NASA astronaut Jerry Linenger discovered at least one oxygen mask on board were malfunctioning as well. The crew managed to contain the fire quickly. Even though it affected life aboard the station for a while afterwards, the crew survived, did not need to evacuate, and helped NASA learn lessons that they still use aboard the International Space Station today.
STS-51F: Abort to orbit (1985)
STS-51F aborted to orbit during its launch. Credit: NASA
The crew of space shuttle Challenger endured two aborts on this mission. The first one took place at T-3 seconds on July 12, when a coolant valve in one of the shuttle’s engines malfunctioned. NASA fixed the problem, only to face another abort situation shortly after liftoff on July 29. One of the engines shut down too early, forcing the crew to abort to orbit. The crew was able to carry on its mission, however, including many science experiments aboard Spacelab.
STS-114: Foam hitting Discovery (2005)
Discovery during STS-114, as seen from the International Space Station. CREDIT: NASA
When Discovery lifted off in 2005, the fate of the entire shuttle program was resting upon its shoulders. NASA had implemented a series of fixes after the Columbia disaster of 2003, including redesigning the process that led to foam shedding off Columbia’s external tank and breaching the shuttle wing. Wayne Hale, a senior official in the shuttle program, later recalled his terror when he heard of more foam loss on Discovery: “I think that must have been the worst call of my life. Once earlier I had gotten a call that my child had been in an auto accident and was being taken to the hospital in an ambulance. That was a bad call. This was worse.” The foam, thankfully, struck nothing crucial and the crew survived. NASA later discovered the cracks in the foam are linked to changes in temperature the tank undergoes, and made more changes in time for a much more successful mission in 2006.
We’ve probably missed some scary moments in space, so which ones do you recall?
Elliott See (left) and Charlie Bassett, who were slated to fly aboard the Gemini 9 mission. Credit: NASA
On this day (Feb. 28) in 1966, the Gemini 9 prime crew was in a T-38 airplane making a final approach to a McDonnell Aircraft plant in St. Louis, Missouri. Amid deteriorating weather conditions, Elliot See tried to make a landing. His airplane collided with the factory building in which his spacecraft was under construction. The plane crashed, killing both See and his crewmate Charlie Bassett.
The accident sent shockwaves through the small astronaut corps, and also necessitated some hasty reassignments. The Gemini 9 backup crew of Tom Stafford and Eugene Cernan immediately became the prime crew and launched into space on May 17, 1966 on a mission that included a challenging spacewalk for Cernan.
But according to Deke Slayton, who was responsible for crew selections at the time, the deaths of See and Bassett even affected the Moon missions of Apollo.
“I … had a lot of plans for Charlie Bassett — after GT-9 [Gemini 9] he would have moved on to command module pilot for Frank Borman’s Apollo crew. Elliott was going to be backup commander for GT-12,” wrote Slayton in his memoir Deke!, which he created with help from Twilight Zone writer (and multiple book author) Michael Cassutt.
In Slayton’s mind, the loss of this one crew affected assignments all the way to the first crew who landed on the Moon: Neil Armstrong and Buzz Aldrin on Apollo 11. (Michael Collins was also on the mission, but remained in orbit in the command module.)
Buzz Aldrin on the Moon for Apollo 11. Credit: NASA
“All the backups were changed, and Jim Lovell and Buzz Aldrin wound up being pointed at GT-12,” Slayton wrote. “Without flying GT-12, it was very unlikely that Buzz would have been in any position to be lunar module pilot on the first landing attempt.”
It’s possible this crash could even have affected Apollo 13, which happened four years later.
Jim Lovell flew on Apollo 8 as the command module pilot. While Slayton didn’t state it, Lovell’s experience on that mission likely led to his appointment as commander for Apollo 14. Fate then shifted him forward a flight to the ill-fated Apollo 13, which was crippled by an oxygen tank explosion, after the original commander of that flight, Al Shepard, required a little more time for training.
As for See and Bassett, their remains were buried at Arlington National Cemetery, which is also home to many other fallen crews. Several crew members from Apollo 1, the Challenger disaster and the Columbia disaster have been laid to rest there.
Bruce McCandless testing out the ultimate jetpack during STS-41B in February 1984. Credit: NASA
The official name is “extra-vehicular activity,” (EVA) but most of us like to call it a spacewalk. However, when you think about it, you don’t really walk in space. You float.
Or more properly speaking, clutch on to handlebars as you make your way from spot to spot on your spacecraft as you race against the clock to finish your repair or whatever outdoor tasks you were assigned. But hey, the view more than makes up for the hard work.
Some astronauts actually got to fly during their time “outside.” During STS-41B 29 years ago this month, Bruce McCandless was the first one to strap on a jetpack and, in science fiction style, float a little distance away from the shuttle.
He called his test of the manned maneuvering unit “a heck of a big leap”. Nearly 30 years after the fact, it still looks like a gutsy move.
What other memorable floating NASA spacewalks have we seen during the space age? Here are some examples:
The first American one
Ed White did the first American spacewalk in 1965. Credit: NASA
The pictures for Ed White’s spacewalk on Gemini 4 still look amazing, nearly 48 years after the fact. The astronaut tumbled and spun during his 23-minute walk in space, and even tested out a small rocket gun until the gas ran out. When commander Jim McDivitt ordered him back inside, the astronaut said it was the saddest moment in his life.
The dancing-with-exhaustion one
Eugene Cernan during his spacewalk on Gemini 9. Credit: NASA
On Gemini 9, which took place the year after Gemini 4, Eugene Cernan was tasked with a spacewalk that was supposed to test out a backpack to let him move independently of the spacecraft.
Cernan, however, faced a lack of handholds and physical supports as he clambered outside towards the backpack. Putting it on took almost all the strength out of him, as he had nowhere to hold on to counterbalance himself.
“Lord, I was tired. My heart was motoring at about 155 beats per minute, I was sweating like a pig, the pickle was a pest, and I had yet to begin any real work,” Cernan wrote in his memoir, Last Man on the Moon, about the experience.
The situation worsened as his visor fogged up and Cernan struggled unsuccessfully to use the backpack. Cernan was so exhausted that he could barely get inside the spacecraft. “I was as weary as I had ever been in my life,” he wrote.
The three-astronauts-outside one
Three astronauts grab the Intelsat VI satellite during the STS-49 mission. Credit: NASA
Spacewalks traditionally (at least, in the shuttle and station era) happen in pairs, so that if one person runs into trouble there’s another to help him or her out. However, two astronauts working outside during STS-49 couldn’t get enough of a grip on the free-flying Intelsat VI satellite they were trying to fix. So NASA elected to do another spacewalk with a third man.
Pierre Thuot hung on the Canadarm while Richard Hieb and Thomas Akers attached their bodies to the payload bay. Having three men hanging on to the satellite provided enough purchase for the astronauts inside the shuttle to maneuver Endeavour to a spot where Intelsat VI could be attached to the payload bay.
The facing-electrical-shock one
Scott Parazynski repaired a damaged solar panel on the space station. Credit: NASA
In 2007, the astronauts of STS-120 unfolded a solar array on the International Space Station and saw — to everyone’s horror — that some panels were torn. Veteran spacewalker Scott Parazynski was dispatched to the rescue. He rode on the end of the Canadarm2, dangling above a live set of electrified panels, and carefully threaded in a repair.
In an interview with Parazynski that I did several years ago, I asked how he used his medical training while doing the repair. Parazynski quipped something along the lines of, “Well, the top thing in my mind was ‘First do no harm.’ ”
The International Space Station construction ones
Sunita Williams appears to touch the sun during this spacewalk on Expedition 35, which took place on the completed International Space Station. Credit: NASA
Spacewalks used to be something extra-special, something that only happened every missions or, on long-duration ones, maybe once. Building the International Space Station was different. The astronauts brought the pieces up in the shuttle and installed them themselves.
The station made spacewalking routine, or as routine such a dangerous endeavour can be. For that reason, an honorary mention goes to every mission that built the ISS.
What are your favorite EVAs? Feel free to add yours to the comments.
Composite Image of NGC 5189 Courtesy of Robert Gendler
Stretching across three light years of space and located about 3,000 light years away in the direction of the constellation of Musca, an incredible and rather understudied planetary nebula awaits a new hand to bring out new light. While most planetary nebula have a rather normal, bloated star look, NGC 5189 shows an extraordinary amount of loops and curls not normally seen in objects of its type. Just what is going on here?
This incredibly detailed image comes from the one and only Robert Gendler and was assembled from three separate data sources. The detail for the nebula is from Hubble Space Telescope data, the background starfield from the Gemini Observatory/AURA and the color data from his own equipment. Here we see fanciful gas clouds with thick clumps decorating them. Intense radiation and gas streams from the central dying star in waves, fashioning out hollows and caves in the enveloping clouds. While these clumps in the clouds may appear as wispy details, each serves as a reminder of just how vast space can be… for each an every one of them is about the same size as our Solar System.
“The complex morphology of this PN is puzzling and has not been studied in detailed so far. Our investigation reveals the presence of a new dense and cold infrared torus (alongside the optical one) which probably generated one of the two optically seen bipolar outflows and which might be responsible for the twisted appearance of the optical torus via an interaction process.” says L. Sabin (et al). ” The high-resolution MES-AAT spectra clearly show the presence of filamentary and knotty structures as well as three expanding bubbles. Our findings therefore suggest that NGC 5189 is a quadrupolar nebula with multiple sets of symmetrical condensations in which the interaction of outflows has determined its complex morphology.”
And just as incredibly large as some things can be – others can be as small. At the heart of NGC 5189 shines the tiny light of its central star… no bigger than Earth. It wobbles its way through time, rotating rapidly and spewing material into space like a runaway fire hydrant. Astronomers speculate there might be a binary star hidden inside, since usually planetary nebulae of this type have them. However, only one star has been found at the nebula’s center and it might be one very big, very bad wolf.
“Around 15% are known or suspected binaries, while the remaining 18% are non-emission line nuclei which require further study. Selecting for LIS (low ionization structures) therefore will give a mix of mostly binary and emission line nuclei which will require further observations to separate.” explains B. Miszalski (et al). “Almost all the [WR] CSPN in the sample belong to the hot [WO] type that have more extreme and chaotic LIS covering their entire nebulae, presumably due to turbulence from the strong [WR] winds disrupting pre-existing LIS.”
Just why is this celestial tapestry so complicated and complex? The answer isn’t a simple one – it’s one that has many plausible theories. We know that when a star similar to the Sun expends its fuel, it will begin to shed its outer layers… layers which normally take on very basic shape. These “normal” shapes are usually a sphere, sometimes a double lobe and at times it can be a ring or helix. However, NGC 5189 just doesn’t follow rules. Over time, researchers have speculated it has given off different outlfows at different stages – one prominent as a very visible torus situated around mid-point in the structure – consistent with the theory of a binary star system with a precessing symmetry axis. Still, there is clearly more research needed.
“Our preliminary results of a comparative spectroscopic study of these two objects shows that the chemical composition of the two nebulae is completely different, even though their morphology is most probably quite similar.” says VF Polcaro (et al). ” In addition, the PN appears much more chemically homogeneous. These features are clearly associated with the evolutionary paths of the stars.”
“The striking broad emission line spectroscopic appearance of Wolf-Rayet (WR) stars has long defied analysis, due to the extreme physical conditions within their line and continuum forming regions.” explains Paul Crowther. “Theoretical and observational evidence that WR winds depend on metallicity is presented, with implications for evolutionary models, ionizing fluxes, and the role of WR stars within the context of core-collapse supernovae and long-duration gamma ray bursts.”
Is NGC 5189 the handiwork of a binary star? Or is it the product of an intensely hot Wolf-Rayet? Like the proverbial Tootsie Pop equation… the world may never know.
Many thanks to Robert Gendler for sharing this incredible image with us.
The Gemini Multi-Object Spectroraph on the Fredrick C. Gillett Gemini North Telescope on Mauna Kea in Hawaii captured this beautiful image of the ring galaxy NGC 660. The galaxy lies about 40 million light-years from Earth toward the constellation Pisces the Fishes. The field of view of the zoomed out image is 9.3×5.6 arcminutes. North is to the right and east is up. Total exposure for the image for all filters was 1,620 seconds. Credit: Gemini Observatory/AURA.
Strings of gas and dust, the wreckage of a colossal galactic struggle, lie strewn and littered about polar-ring galaxy NGC 660 in this new image from the Gemini Observatory.
Zoom around the ring of stars, stop to dive into massive star clusters and pink nebulae rich with the birth of new stars. Astronomers have found only a few of these bizarre objects. Most are made up of an early-type spiral galaxy, known as a lenticular galaxy, surrounded by a vast ring of stars extending for tens of thousands of light-years nearly perpendicular to the plane of the main galaxy. NGC 660, however, is the only polar-ring galaxy with a late-type lenticular galaxy as host.
NASA has published a new online gallery of beautifully restored photographs from the historic Project Gemini of the 1960s, the second U.S. manned spaceflight program. The digitally remastered photos have been scanned from the original film, showing highlights of Project Gemini in beautifully enhanced colour and detail.
Project Gemini followed the initial Project Mercury program and was the predecessor for the ambitious Apollo missions to the Moon, with ten crewed flights from 1965-1966. It used a two-man spacecraft and tested new technologies and procedures for the later Apollo missions such as precision atmospheric reentry, Extra Vehicular Activity (spacewalking), fuel cells to generate electricity and water, perfect the rendezvous and docking process between two spacecraft, new techniques for propelling and maneuvering two docked spacecraft and long-term human spaceflight.
It featured the first spacewalk, the first rendezvous between two Gemini spacecraft, the first docking between a manned and unmanned vehicle, the first maneuver to change orbit and the first onboard computer.
Gemini VII's rendezvous with Gemini VI. Credit: NASA / JSC / Arizona State University
The photo gallery is part of the March to the Moon website archive, which also has restored photo galleries from the Mercury missions as well as background information on the missions, Quicktime video clips and links to additional resources.
Gemini South laser guide star system propagating as the Milky Way rises.
[/caption]When it comes to astrophotography, most of us would think that space-based telescopes like the Hubble are the epitome of imagining. However, there’s something new to be said about being “grounded”. On December 16, 2011, the Gemini South telescope in Chile revealed its first wide-field, ultra-sharp image… the product of a decade of hard work. By employing a new generation of adaptive optics (AO), the scope produced an incredible look into the densely concentrated globular cluster, NGC 288, and captured stars at close to the theoretical resolution limit of Gemini’s massive 8-meter mirror.
The Gemini Multi-conjugate adaptive optics System (GeMS for short), produced an incredible vision… one of incredible resolution. This new system will allow astronomers to study galactic centers and their black holes – as well as the life patterns of singular stars – with incredible clarity. It’s the largest amount of area ever captured in a single observation – one that’s ten times larger than any adaptive optics systems has ever been able to capture before. It has cause quite a stir in the astronomical community. When Space Telescope Science Institute director Matt Mountain saw the first light image, he praised the GeMS instrument team: “Incredible! You have truly revolutionized ground-based astronomy!”
As the director of the Gemini Observatory, Dr. Mountain was around when the project first began 10 years ago. He was responsible for assembling the team, including Francois Rigaut as the lead scientist to develop the GeMS instrument. And, Rigaut was there for first light… “We couldn’t believe our eyes!” Rigaut recalls. “The image of NGC 288 revealed thousands of pinpoint stars. Its resolution is Hubble-quality – and from the ground this is phenomenal.” Of course, one of the most amazing aspects of the image was how widely spaced the stars appeared, to which Rigaut comments: “This is somewhat uncharted territory: no one has ever made images so large with such a high angular resolution.”
Gemini South’s “first light” image from GeMS/GSAOI shows extreme detail in the central part of the globular star cluster NGC 288. The image, taken at 1.65 microns (H band) on December 16, 2011, has a field-of-view 87 x 87 arcseconds. The average full-width at half-maximum is slightly below 0.080 arcsecond, with a variation of 0.002 arcsecond across the entire field of the image. Exposure time was 13 minutes. Insets on the right show a detail of the image (top), a comparison of the same region with classical AO (middle; this assumes using the star at the upper right corner as the guide star), and seeing-limited observations (bottom). The pixel size in the latter was chosen to optimize the signal-to-noise ratio while not degrading the intrinsic angular resolution of the image. North is up, East is right.
Even though this is an incredible insight, some members of the scientific team which use the Gemini telescope are a bit more reserved in their comments. According to University of Toronto astronomer Roberto Abraham, one of a community of hundreds of astronomers worldwide who uses the 8-meter Gemini telescopes for cutting-edge research: “This is fan-freaking-tastic!!!!!!!” Exuberant? Of course! Even the environmental conditions remained as perfect as they could be for the first run of the GeMS equipment. “We were lucky to have clear weather and stable atmospheric conditions that night,” said Gemini AO scientist Benoit Neichel. “Even despite interruptions of the laser propagation due to satellites and planes passing by, we obtained our first image with the system. It was surprisingly crisp and large, with an exquisitely uniform image quality.”
How is it accomplished? GeMS employs five laser guide stars, three deformable mirrors and a full arsenal of computers to provide a near diffraction limited image to the Gemini South Adaptive Optics Imager (GSAOI, built by the Australian National University) and the infrared-sensitive imager attached to it. This means the smallest detail that can be resolved measures about 0.04 to 0.06 arcsecond over a field of 85 arcseconds squared. Compared to 0.5 arcsecond “seeing limited” at a good viewing location, that’s phenomenal! Once resolution was solved, the next problem was extending the field of view through a technique called Multi-Conjugate Adaptive Optics (MCAO) – an endeavor which borrowed technology from other scientific fields, such as medical imaging.
“MCAO is game-changing,” Abraham said. “It’s going to propel Gemini to the next echelon of discovery space as well as lay a foundation for the next generation of extremely large telescopes. Gemini is going to be delivering amazing science while paving the way for the future.”
KENNEDY SPACE CENTER, Fla – Every year the Astronaut Scholarship Foundation (ASF) hosts its “Astronaut Autograph Show” at Kennedy Space Center in Florida. This year it was held on Nov. 5-6 at the Kennedy Space Center Visitor Complex’s Debus Center. The ASF coordinated with the operators of the Cocoa Beach Air Show to ensure that the show had a very dramatic ending. Continue reading “ASF 2011 Autograph Show: To Be the Shoulders of Tomorrow’s Titans”
The circled cluster of stars is the dwarf galaxy Andromeda 29, which University of Michigan astronomers have discovered. The bright star within the circle is a foreground star within our own Milky Way galaxy. This image was obtained with the Gemini Multi-Object Spectrograph at the Gemini North telescope in Hawaii. Credit: Gemini Observstory/AURA/Eric Bell
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Yep. It’s that time of year again. Time to enjoy the Andromeda Galaxy at almost every observing opportunity. But now, rather than just look at the nearest spiral to the Milky Way and sneaking a peak at satellites M32 and M110, we can think about something more when we peer M31’s way. There are two newly discovered dwarf galaxies that appear to be companions of Andromeda!
Eric Bell, an associate professor in astronomy, and Colin Slater, an astronomy Ph.D. student, found Andromeda 28 and Andromeda 29 by utilizing the Sloan Digital Sky Survey and a recently developed star counting technique. To back up their observations, the team employed data from the Gemini North Telescope in Hawaii. Located at 1.1 million and 600,000 light-years respectively, Andromeda XXVIII and Andromeda XXIX have the distinction of being the two furthest satellite galaxies ever detected away from the host – M31. Can they be spotted with amateur equipment? Not hardly. This pair comes in about 100,000 fainter than Andromeda itself and can barely be discerned with some of the world’s largest telescopes. They’re so faint, they haven’t even been classified yet.
“With presently available imaging we are unable to determine whether there is ongoing or recent star formation, which prevents us from classifying it as a dwarf spheroidal or a dwarf irregular.” explains Bell.
The dwarf galaxy Andromeda 29, which University of Michigan astronomers have discovered, is clustered toward the middle of this image, obtained with the Gemini North telescope in Hawaii. Credit: Gemini Observstory/AURA/Eric Bell
In their work – published in a recent edition of the edition of the Astrophysical Journal Letters – the team of Bell and Slater explains how they were searching for dwarf galaxies around Andromeda to help them understand how physical matter relates to theoretical dark matter. While we can’t see it, hear it, touch it or smell it, we know it’s there because of its gravitational influence. And when it comes to gravity, many astronomers are convinced that dark matter plays a role in organizing galaxy structure.
“These faint, dwarf, relatively nearby galaxies are a real battleground in trying to understand how dark matter acts at small scales,” Bell said. “The stakes are high.”
Right now, current consensus has all galaxies embedded in surrounding dark matter… and each “bed” of dark matter should have a galaxy. Considering the volume of the Universe, these predictions are pretty much spot on – if we take only large galaxies into account.
“But it seems to break down when we get to smaller galaxies,” Slater said. “The models predict far more dark matter halos than we observe galaxies. We don’t know if it’s because we’re not seeing all of the galaxies or because our predictions are wrong.”
“The exciting answer,” Bell said, “would be that there just aren’t that many dark matter halos.” Bell said. “This is part of the grand effort to test that paradigm.”
Right or wrong… pondering dark matter and dwarf galaxies while observing Andromeda will add a whole new dimension to your observations!
For Further Reading: Andromeda XXVIII: A Dwarf Galaxy more than 350 kpc from Andromeda and Andromeda XXIX: A New Dwarf Spheroidal Galaxy 200 kpc from Andromeda.
